<!-- This defines instructions described in PowerISA Version 3.0 B Book 1 -->

<!-- This defines instructions that load from RAM to a register -->

<!-- Note that these pages also define equivalent store instructions, -->
<!-- these are described in fixedstore.mdwn -->

<!-- Section 3.3.2 This defines the Fixed-Point Load Instructions pages 47 - 53 -->
<!-- Section 3.3.3 Fixed-Point Store Instructions pages 54 - 56 -->
<!-- Section 3.3.3.1 64-bit Fixed-Point Store Instructions pages 57 -->
<!-- Section 3.3.4 Fixed Point Load and Store Quadword Instructions pages 58 - 59 -->
<!-- Section 3.3.5 Fixed-Point Load and Store with Byte Reversal Instructions page 60 -->
<!-- Section 3.3.5.1 64-Bit Load and Store with Byte Reversal Instructions page 61 -->
<!-- Section 3.3.6 Fixed-Point Load and Store Multiple Instructions page 62 -->


<!-- Section 3.3.2 This defines the Fixed-Point Load Instructions pages 47 - 53 -->

<!-- The byte, halfword, word, or doubleword in storage addressed by EA is loaded -->
<!-- into register RT. -->

<!-- Many of the Load instructions have an “update” form, in which register RA is -->
<!-- updated with the effective address. For these forms, if RA!=0 and RA!=RT, the -->
<!-- effective address is placed into register RA and the storage element (byte, -->
<!-- halfword, word, or doubleword) addressed by EA is loaded into RT. -->


# Load Byte and Zero

D-Form

* lbz RT,D(RA)

Pseudo-code:

    b <- (RA|0)
    EA <- b + EXTS(D)
    RT <- ([0] * (XLEN-8)) || MEM(EA, 1)

Description:

Let the effective address (EA) be the sum (RA|0)+ D.
The byte in storage addressed by EA is loaded into
RT[56:63]. RT[0:55] are set to 0.

Special Registers Altered:

    None

# Load Byte and Zero Indexed

X-Form

* lbzx RT,RA,RB

Pseudo-code:

    b <- (RA|0)
    EA <- b + (RB)
    RT <- ([0] * (XLEN-8)) || MEM(EA, 1)

Special Registers Altered:

    None

# Load Byte and Zero with Update

D-Form

* lbzu RT,D(RA)

Pseudo-code:

    EA <- (RA) + EXTS(D)
    RT <- ([0] * (XLEN-8)) || MEM(EA, 1)
    RA <- EA

Special Registers Altered:

    None

# Load Byte and Zero with Update Indexed

X-Form

* lbzux RT,RA,RB

Pseudo-code:

    EA <- (RA) + (RB)
    RT <- ([0] * (XLEN-8)) || MEM(EA, 1)
    RA <- EA

Description:Let the effective address (EA) be the sum (RA)+ (RB).
The byte in storage addressed by EA is loaded into
RT56:63. RT0:55 are set to 0.
EA is placed into register RA.
If RA=0 or RA=RT, the instruction form is invalid.

Special Registers Altered:

    None

# Load Halfword and Zero

D-Form

* lhz RT,D(RA)

Pseudo-code:

    b <- (RA|0)
    EA <- b + EXTS(D)
    RT <- ([0] * (XLEN-16)) || MEM(EA, 2)

Special Registers Altered:

    None

# Load Halfword and Zero Indexed

X-Form

* lhzx RT,RA,RB

Pseudo-code:

    b <- (RA|0)
    EA <- b + (RB)
    RT <- ([0] * (XLEN-16)) || MEM(EA, 2)

Special Registers Altered:

    None

# Load Halfword and Zero with Update

D-Form

* lhzu RT,D(RA)

Pseudo-code:

    EA <- (RA) + EXTS(D)
    RT <- ([0] * (XLEN-16)) || MEM(EA, 2)
    RA <- EA

Special Registers Altered:

    None

# Load Halfword and Zero with Update Indexed

X-Form

* lhzux RT,RA,RB

Pseudo-code:

    EA <- (RA) + (RB)
    RT <- ([0] * (XLEN-16)) || MEM(EA, 2)
    RA <- EA

Special Registers Altered:

    None

# Load Halfword Algebraic

D-Form

* lha RT,D(RA)

Pseudo-code:

    b <- (RA|0)
    EA <- b + EXTS(D)
    RT <- EXTS(MEM(EA, 2))

Special Registers Altered:

    None

# Load Halfword Algebraic Indexed

X-Form

* lhax RT,RA,RB

Pseudo-code:

    b <- (RA|0)
    EA <- b + (RB)
    RT <- EXTS(MEM(EA, 2))

Special Registers Altered:

    None

# Load Halfword Algebraic with Update

D-Form

* lhau RT,D(RA)

Pseudo-code:

    EA <- (RA) + EXTS(D)
    RT <- EXTS(MEM(EA, 2))
    RA <- EA

Special Registers Altered:

    None

# Load Halfword Algebraic with Update Indexed

X-Form

* lhaux RT,RA,RB

Pseudo-code:

    EA <- (RA) + (RB)
    RT <- EXTS(MEM(EA, 2))
    RA <- EA

Special Registers Altered:

    None

# Load Word and Zero

D-Form

* lwz RT,D(RA)

Pseudo-code:

    b <- (RA|0)
    EA <- b + EXTS(D)
    RT <- [0] * 32 || MEM(EA, 4)

Special Registers Altered:

    None

# Load Word and Zero Indexed

X-Form

* lwzx RT,RA,RB

Pseudo-code:

    b <- (RA|0)
    EA <- b + (RB)
    RT <- [0] * 32 || MEM(EA, 4)

Special Registers Altered:

    None

# Load Word and Zero with Update

D-Form

* lwzu RT,D(RA)

Pseudo-code:

    EA <- (RA) + EXTS(D)
    RT <- [0]*32 || MEM(EA, 4)
    RA <- EA

Special Registers Altered:

    None

# Load Word and Zero with Update Indexed

X-Form

* lwzux RT,RA,RB

Pseudo-code:

    EA <- (RA) + (RB)
    RT <- [0] * 32 || MEM(EA, 4)
    RA <- EA

Special Registers Altered:

    None

# Load Word Algebraic

DS-Form

* lwa RT,DS(RA)

Pseudo-code:

    b <- (RA|0)
    EA <- b + EXTS(DS || 0b00)
    RT <- EXTS(MEM(EA, 4))

Special Registers Altered:

    None

# Load Word Algebraic Indexed

X-Form

* lwax RT,RA,RB

Pseudo-code:

    b <- (RA|0)
    EA <- b + (RB)
    RT <- EXTS(MEM(EA, 4))

Special Registers Altered:

    None

# Load Word Algebraic with Update Indexed

X-Form

* lwaux RT,RA,RB

Pseudo-code:

    EA <- (RA) + (RB)
    RT <- EXTS(MEM(EA, 4))
    RA <- EA

Special Registers Altered:

    None

# Load Doubleword

DS-Form

* ld RT,DS(RA)

Pseudo-code:

    b <- (RA|0)
    EA <- b + EXTS(DS || 0b00)
    RT <- MEM(EA, 8)

Special Registers Altered:

    None

# Load Doubleword Indexed

X-Form

* ldx RT,RA,RB

Pseudo-code:

    b <- (RA|0)
    EA <- b + (RB)
    RT <- MEM(EA, 8)

Special Registers Altered:

    None

# Load Doubleword with Update Indexed

DS-Form

* ldu RT,DS(RA)

Pseudo-code:

    EA <- (RA) + EXTS(DS || 0b00)
    RT <- MEM(EA, 8)
    RA <- EA

Special Registers Altered:

    None

# Load Doubleword with Update Indexed

X-Form

* ldux RT,RA,RB

Pseudo-code:

    EA <- (RA) + (RB)
    RT <- MEM(EA, 8)
    RA <- EA

Special Registers Altered:

    None

<!-- Section 3.3.3 Fixed-Point Store Instructions pages 54 - 56 -->

<!-- The contents of register RS are stored into the byte, halfword, word, or -->
<!-- doubleword in storage addressed by EA. -->

<!-- Many of the Store instructions have an “update” form, in which register RA is -->
<!-- updated with the effective address. For these forms, the following rules apply. -->

<!-- If RA!=0, the effective address is placed into register RA. -->

<!-- If RS=RA, the contents of register RS are copied to the target storage element -->
<!-- and then EA is placed into RA (RS). -->

<!-- Section 3.3.3.1 64-bit Fixed-Point Store Instructions pages 57 -->

<!-- Section 3.3.4 Fixed Point Load and Store Quadword Instructions pages 58 - 59 -->

<!-- For lq, the quadword in storage addressed by EA is loaded into an even-odd pair -->
<!-- of GPRs as follows. In Big-Endian mode, the even-numbered GPR is loaded with -->
<!-- the doubleword from storage addressed by EA and the odd-numbered GPR is loaded -->
<!-- with the doubleword addressed by EA+8. In Little-Endian mode, the even-numbered -->
<!-- GPR is loaded with the byte-reversed doubleword from storage addressed by EA+8 -->
<!-- and the odd-numbered GPR is loaded with the byte-reversed doubleword addressed -->
<!-- by EA. -->

# Load Quadword

DQ-Form

* lq RTp,DQ(RA)

Pseudo-code:

    b <- (RA|0)
    EA <- b + EXTS(DQ || 0b0000)
    RTp <- MEM(EA, 16)

Special Registers Altered:

    None

<!-- Section 3.3.5 Fixed-Point Load and Store with Byte Reversal Instructions page 60 -->

# Load Halfword Byte-Reverse Indexed

X-Form

* lhbrx RT,RA,RB

Pseudo-code:

    b <- (RA|0)
    EA <- b + (RB)
    load_data <- MEM(EA, 2)
    RT <- [0]*48 || load_data[8:15] || load_data[0:7]

Special Registers Altered:

    None

# Load Word Byte-Reverse Indexed

X-Form

* lwbrx RT,RA,RB

Pseudo-code:

    b <- (RA|0)
    EA <- b + (RB)
    load_data <- MEM(EA, 4)
    RT <- ([0] * 32 || load_data[24:31] || load_data[16:23]
                    || load_data[8:15]  || load_data[0:7])

Special Registers Altered:

    None


<!-- Section 3.3.5.1 64-Bit Load and Store with Byte Reversal Instructions page 61 -->

# Load Doubleword Byte-Reverse Indexed

X-Form

* ldbrx RT,RA,RB

Pseudo-code:

    b <- (RA|0)
    EA <- b + (RB)
    load_data <- MEM(EA, 8)
    RT <- (load_data[56:63] || load_data[48:55]
        || load_data[40:47] || load_data[32:39]
        || load_data[24:31] || load_data[16:23]
        || load_data[8:15]  || load_data[0:7])

Special Registers Altered:

    None

<!-- Section 3.3.6 Fixed-Point Load and Store Multiple Instructions page 62 -->

# Load Multiple Word

DQ-Form

* lmw RT,D(RA)

Pseudo-code:

    b <- (RA|0)
    EA <- b + EXTS(D)
    r <- RT[0:63]
    do while r <=  31
        GPR(r) <- [0]*32 || MEM(EA, 4)
        r <- r + 1
        EA <- EA + 4

Special Registers Altered:

    None